1. Field of the Invention
The present invention relates to a cellular telephone with photographing capability, and particularly, a foldable cellular telephone.
2. Description of the Background Art
Cellular telephones now widely used are mainly divided into a straight type, a flip type, and a clam shell type, based on their configuration. The clam shell type phone has higher needs than the other two types by virtue of its compactness allowed by its foldability.
Many recent cellular/mobile telephones incorporate a liquid crystal subdisplay or a camera function at the back side plane of the liquid crystal display.
FIG. 10 shows an example of a conventional clam shell type cellular phone with a camera. This cellular phone 100 is composed of a first case 101 and a second case 102, which are coupled via a hinge 103. Cellular phone 100 has a foldable configuration through the movement with hinge 103 as the axis in angular displacement. Cellular phone 100 of FIG. 10 has a first display unit 104 provided at first case 101. First display unit 104 is arranged so as to be located at the inner side when cellular phone 101 is folded. First display unit 104 (main display) is implemented with a liquid crystal display, an EL (Electro-Luminescent) display, or the like to display an image based on image data transmitted via a first display driver provided in the case. At the back side plane of first case 101 are provided an antenna unit 105 and a helical member 106 that can move up and down. At the side plane of first case 101 is provided a second shutter button 107 of a camera. At the region above first display unit 104, a first speaker 108 used in conversation is provided.
An open/close detection unit 109 is identified as detection means for detecting whether cellular phone 100 attains a folded state or not. A projection 109A is located in the proximity of hinge 103 at the lower region of first case 101. A small hole 109B is located in the proximity of hinge 103 at the upper region of second case 102. A detection switch (not shown) is provided in hole 109B. Projection 109A, hole 109B and the switch constitute open/close detection unit 109. When mobile telephone 100 attains a folded state, projection 109A of first case 101 fits into hole 109B of second case 102 to actuate the detection switch (not shown). Determination is made that cellular phone 100 attains a folded state by means of a control unit provided in the case.
Second case 102 of conventional cellular phone 100 will be described hereinafter. An input button unit 110 is formed of keys and the like to enter numerics and characters. A function button unit 111 is a group of buttons for performing various kinds of setting and function selection in a cellular phone. Function button unit 111 includes a power button 112 to turn the power on/off, a first shutter button 113 corresponding to a camera function that will be described afterwards, a mail/guidance button 114 to conduct mail operation and guidance display, a start/speaker conversation button 115 to initiate conversation through speaker receiver, and a multi-guide button 116 formed of 4-way buttons and a determination button to select and determine the vertical and horizontal direction in the function select screen. A mouthpiece microphone 117 is provided at the lower region of second case 102.
Second case 102 of a common cellular phone generally has the arrangement of hinge 103, function button group 111, input button group 110, and mouthpiece microphone 117 disposed sequentially.
Referring to FIG. 11, the back side plane of first case 101 includes a second display unit 120, a camera unit 121, a light unit 122, and the aforementioned antenna unit 105.
Second display unit 120 is arranged so as to be located at the outer side when cellular phone 100 is folded. Second display unit 120 (subdisplay) is implemented with a liquid crystal display, an EL display, or the like to display an image based on image data transmitted via a second display driver provided in the case.
Camera unit 121 includes an image sensing lens, an image sensing device such as a CCD (Charged Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and a color filter of the three colors of RGB (Red-Green-Blue). In camera unit 2, the light reflected from a subject of image pick up enters the image sensing lens to be converted into light of the three colors of RGB through a color filter, and further provided to said image sensing device. As shown in FIG. 11, camera unit 121 is disposed to be located at the outer side when cellular phone 100 is folded.
Light unit 122 is used as an auxiliary light source when taking a picture through camera unit 121. Although many employ xenon tubes, recent cellular phones have the LEDs (Light Emitting Diode) of RGB illuminated at the same time to provide white light illumination used as the auxiliary light source.
At the back side plane of second case 102 are provided a battery unit 123 to store a battery, and a second speaker 124 to sound a ringing tone.
The manner of using conventional cellular phone 100 in a camera shooting mode will be described hereinafter with reference to FIGS. 14A and 14B. In the case where the user of cellular phone 100 is to take a picture of a subject, the user of cellular phone 100 opens cellular phone 100 and aims camera unit 121 towards the subject of interest, as shown in FIG. 14A. First display unit 104 is used as a viewfinder. In the case where the user of cellular phone 100 is to take a picture of himself/herself, the user can pick up an image while confirming the shooting image by using second display unit 120 as the viewfinder, as shown in FIG. 14B. In the latter case where second display unit 120 is used for the display in camera shooting, many common cellular phones have the image reversed bilaterally to be displayed as a mirror reversed image to eliminate any discomfort in looking into the screen. As the camera shutter button, either first shutter button 113 or second shutter button 107 located at the side plane of first case 101 may be used when in the state corresponding to FIG. 14A. In the state corresponding to FIG. 14B, second shutter button 107 is used for shooting with cellular phone 100 in a folded state. However, shooting in an open state is also allowed. In this case, second shutter button 107 located at the side plane of first case 101 is to be used.
The above-described clam shell type onboard camera cellular phone including two display means has various shortcomings.
The first problem is the matter of changing the hand holding position. As to the vertical orientation of the clam shell type cellular phone in an open state and a folded state, the cellular phone is used with helical member 106 located at the upper side as shown in FIGS. 10 and 12, respectively. Therefore, when the user takes a picture of himself/herself with cellular phone 100 closed (refer to FIG. 14B), and then proceeds to the next operation of shooting a different subject (refer to FIG. 14A) or conducting various image settings through first display unit 104, the user must change his/her hand holding position by rotating 180 degrees the top and bottom position of cellular phone 100, and then open cellular phone 100.
In the case where cellular phone 100 is to be used in an open state after looking at a mail message, an incoming phone call designation, or the time through second display unit 120, the hand holding position of cellular phone 100 must be changed by rotating cellular phone 100 upside down, and then open cellular phone 100.
In the opposite case where cellular phone 100 is to be used in a folded state from an open state, the hand holding position of cellular phone 100 must be changed in the opposite direction after being folded. The action of changing the hand holding position to appropriately match the usage manner of the cellular phone is tedious for the user.
The second problem is that antenna unit 105 provided at the back side plane of first case 101 occupies a relatively large region. The trend in cellular phones is to provide a larger area of second display unit 120, i.e., the subdisplay at the back side plane, so that more information can be displayed for the user even if the cellular phone is folded. However, it is appreciated from FIGS. 11 and 12 that antenna unit 105 occupies a relatively large area at the back side plane of first case 101, restricting the degree of freedom in the arrangement of subdisplay unit 120. It was not possible to provide a large area for the subdisplay.
The third problem is also associated with the antenna. Antenna unit 105 is formed having a convex configuration at the back side plane of first case 101. If buttons such as the shutter button and subdisplay operation buttons are to be provided at this back side plane, antenna unit 105 will cause inconvenience in the operation of the user depressing such buttons with his/her finger. There was a problem that button manipulation is disturbed.
The fourth problem is related to the compactness of a cellular phone. Although the demand for a compact cellular phone is mandatory, cellular phone 100 with a camera must have a predetermined thickness to incorporate the lens and the CCDs constituting camera unit 21. In the case where the camera unit is disposed at the leading end of first case 101, the leading end cannot be reduced in thickness since the thickness to accommodate the camera unit is required. In the opposite case where the camera unit is disposed at the hinge side, the user's hand may block the field of view of the lens when shooting is conducted with cellular phone 100 in a folded state. This is not adaptable to practicable usage.
The fifth problem is associated with hand shaking. In the case where the camera unit is disposed at the leading end of first case 101 and shooting is to be conducted with the cellular phone in an open state, the camera unit will be located far away from the hand of the user who is holding second case 102. Therefore, the effect of hand shaking is greatest under such circumstances. If the camera unit is disposed at the hinge side and shooting is to be conducted with cellular phone 100 in a folded state, the user's hand may block the field of view of the lens, as described in the above fourth problem. Therefore, this is not adaptable to practical usage.